Reliability is achieved by conservative design wherein parts are physically loaded to stresses far below their yield point and wherein duplicate mechanisms are provided for those parts which have the highest failure rates, even with conservative design. In some environments, the weight associated with conservative design is also a negative factor. The sheer cost of the additional material and the machine time involved in handling the additional material is only a starting additional cost. In those systems where the mechanism will be involved in transportation, the additional weight will be a continuing penalty. Whether on highway, rail or flying vehicles, the excess weight of conservative design poses a penalty. The penalty becomes quite large in air flight and space flight. As a result of such penalties, original design must incorporate factors which maximize reliability but minimize weight.
The present two-motor redundant drive mechanism is a low weight mechanism with two redundant drive motors and is configured to provide reliable drive for a number of different mechanical devices. While it is useful in a number of land applications, such as applying the brakes on a railroad train, it is particularly useful in aircraft and space applications. For example, it is useful in controlling the flaps or trim tabs in an aircraft and is capable of raising and lowering the landing gear of the aircraft. In space, it is capable of raising an antenna from a stowed to a deployed position.